CLOSING TIME: Yankees closer Mariano Rivera has hinted this will be his last season. Once he does retire, the Yankees face the tall task of replacing a legend. Photo: Charles Wenzelberg/New York Post

TAMPA — If this were just about replacing a closer — even a legendary closer — then the Yankees would have a difficult, yet plausible, job ahead.

But if this really is Mariano Rivera’s last season, then the Yankees are on the clock toward something much more difficult:

Replacing a feeling.

It is not that Rivera avoided all failure. Heck, he blew Game 7 of the World Series. But, even when that ended the 2001 season, no one with the Yankees fretted for one second how that would impact 2002. Rivera would not be cowed and the internal clubhouse confidence in him would not waver. Ever.

Like aircraft-control operators or field-goal kickers, the closer role has a glorious-success-or-abject-failure dynamic. You either land the plane or you don’t. You either convert the last-second field goal or you are Billy Cundiff or Scott Norwood. You either get the last out with your team ahead or you don’t. No safety net.

Thus the closer, more than anyone else, sets an emotional barometer for your team depending on his trust level within the group. Not just for today, but how he will be tomorrow if today goes poorly.

All closers and cornerbacks, for example, talk about putting failure behind them. However, it takes a certain type of human — or inhuman — to truly excise a fiasco, stay as focused and confident as ever, keep the clubhouse feeling the same about you, prevent the home crowd from projecting a strain of gloom and doom when you enter that metastasizes into the psyches of teammates.

When I asked Russell Martin what he learned playing with Rivera that he could not know from afar, he said, “There is no way, none, that you can tell from his expression or behavior whether he has pitched well or poorly, whether he just saved a big game or blew one in Fenway. There is a sense about him like you are dealing with a wise man who knows the secret you do not.”

And this feeling transfuses into the clubhouse. There never is worry about how the Yankees will close out a game; never a second of concern about whether a blown save on Monday will bleed into Tuesday. With all the storms that brew around the Yankees, there is a team-wide calm created by the man in the job that normally provokes the most organizational agita.

This is because Rivera is the anti-headache. He always is in shape, never in controversy. His confidence and talent are extreme, but so is his sense of responsibility and humility. He relies on one pitch, a cut fastball, but has myriad tools such as unflinching poise, unflagging athleticism and unending competitiveness.

He is not just a closer, but a closer for a perennial contender in New York with a parade-or-bust mindset. His response is somehow to be the greatest regular-season closer ever and, arguably, the greatest postseason player of any position.

That is why Yankees pitching coach Larry Rothschild said, “It is so much more than the numbers he put up [that will have to be replaced].” It is why I kept wondering yesterday if I had stumbled into a Thom McAn rather than George M. Steinbrenner Field, so often did someone invoke the “impossible shoes to fill” theme in describing Rivera.

We all knew this day eventually would come. Rivera gives off the sense he is composed of springs and coils, especially since — if anything — he has kept getting better into his 40s.

“He’s a fine wine,” Rothschild said.

But now Rivera strongly has hinted 2012 will be his final campaign, and suddenly it feels like a six-month audition for David Robertson and Rafael Soriano.

Of course, Rivera was a surprise from nowhere. So I think the Robertson/Soriano speculation is too narrow. Maybe it will be Michael Pineda if he never develops a third pitch or Dellin Betances or Joba Chamberlain or some kid at A-ball with essentially one pitch.

But this will not be like replacing the dynastic Bernie Williams or Andy Pettitte or Jorge Posada. They did not set the tone or style of the team. They could be supported by others if they failed.

The Yankees have grown so addicted to Rivera they concede playing backward, eliminating the ninth inning (and in his younger days the eighth inning, as well), and trying to just figure out how to get the ball to Mo with the lead. He was saver and, so often, savior.